The Horizontal Gaze Nystagmus Test

The Horizontal Gaze Nystagmus (HGN) Test is a fairly new field sobriety test in New Jersey drinking and driving cases. This is one of the field sobriety tests law enforcement officers use when conducting DWI traffic stops. If the breathalyzer or blood test results are not conclusive, the State will attempt to use these field sobriety results to prove intoxication. In State v. Maida 332 NJ Super 564 (Law Div. 2000), the court held that HGN testing is generally accepted in the relevant scientific community. However, absent a similar determination by an Appellate Court or the New Jersey Supreme Court, the trial courts in this State are not at liberty to admit evidence of newly-devised scientific technology unless the general acceptance thereof is demonstrated by expert testimony, authoritative scientific and legal writings or judicial opinions. This issue went to the Appellate Division in the case of State v. Doriguzzi 334 NJ Super 530 (2000) where the Appellate Division declined to take judicial notice of the HGN tests. The court held that HGN testing is scientific in nature and must be supported by expert testimony.

The HGN test is based on the observation of three different physical manifestations which occur when a person is under the influence of alcohol: (1) the inability of a person to follow, visually, in a smooth way, an object that is moved laterally in front of the person’s eyes; (2) the inability to retain focus and the likelihood of jerking of the eyeball when a person has moved his or her eye to the extreme range of peripheral vision; and (3) the reported observation that this “jerking” of the eyeball begins before the eye has moved 45 degrees from forward gaze if the individual’s BAC [ (Blood Alcohol Content) ] is .10 [percent] or higher.